Looking Up: No telescope needed to see neighbor galaxy

Peter Becker More Content Now

Friday

Nov 9, 2018 at 5:01 AM

How far can you see? A lot far than you might ever imagine. With only your eyes, the next clear evening you can gaze heavenward and look millions of light years beyond our Milky Way and see an entirely different galaxy teeming with as many as one trillion stars.

Anyone with eyes to see can do this. You don’t even need an Smartphone app or pay someone for Internet or TV.You don’t even need binoculars, let alone a telescope. Along with a reasonably dark, clear sky, the average pair of eyes can easily spot the Andromeda Galaxy, commonly listed as “M31.”

At around 8 p.m. on an early November night, M31 shines high in the northeast. It is high up in the south around 10 p.m. as seen from mid-northern latitudes; in fact from northeast Pennsylvania where I live, the galaxy is almost overhead at its highest.

To the naked eye from a dark sky, M31 appears like a dim, fuzzy ellipse. Binoculars will bring it out distinctly, showing it as a long ellipse, brightest in the center. This is particularly exciting because you are viewing actual detail including the bright central hub and the dim spiral arms. The Andromeda Galaxy is a classic spiral. Using binoculars won’t see the individual, tapering arms, but rather they blend together as seen from our perspective. We see the galaxy at a foreshortened angle. Hints of the separate arms are visible using a 6” telescope or larger.

Like the Milky Way Galaxy where we hang or hat, the Andromeda spiral is composed of vast amounts of dust, gas and stars. We can be confident that among the trillion stars there are certainly trillions of planets, as yet far beyond our ability to detect.

M31, however, is about twice as large as the Milky Way Galaxy.

M31 has about 14 small satellite galaxies orbiting. Two are easily seen in a telescope of only 3” aperture.

So how far away is the Andromeda Galaxy?

Astronomers have measured the distance to be 2.54 million light years. Each light year is approximately 5.8 trillion miles. A light year is the distance light travels in a year’s time.

M31 is the largest galaxy in the “Local Group” which includes the Milky Way, traveling the Universe together. Yes, we have neighbors, and this one is coming to call.

If you think 2.54 million light years is far, just wait. The Andromeda Galaxy is approaching the Milky Way at a rate of 68 miles a second. A direct collision is expected in 4.5 billion years. Our two galaxies are expected to merge.

Can you imagine how bright and beautiful M31 will appear in the sky, say, 2 billion years from now? Also ,imagine how starry the sky will be when our two galaxies merge!

To find M31, look high in the north for constellation Cassiopeia, its five main stars making a letter “M”. Scan your eyes to the upper right about the same distance as Cassiopeia is long. Binoculars will help.

First quarter Moon is on November 15.

Keep looking up!

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